Electric relay



Dec. 29, 1959 J, sc 2,919,323

ELECTRIC RELAY Filed July 1, 1957 INVENTOR. JOHN F. DRESCHER BY war; a 724115142 0) ATTORNEYS U nited States Patent ()fi 2,919,323 Patented Dec. 29, 1959 ice 2,919,323 v. L crRni RELAY John F.'Drescl1er, Santa Monica, Calif. .ApplicatioitJuly 1,1957, Serial No- 669,231

*6 Claims. Cl. 200-93 This inventiongenerally relates to electric relays and more particularly to a relay having a quick-make quickbreak action designed toperform satisfactorily, particularly under the environmental conditions encountered in aircraft and missile applications.

In conventionalirelay .construction, three normal components are usually employed: a magnetic-coil; amember actuated by the coil; and, means for retaining the member in an unactuated position. The manufacturing problems and operating .difficulties I associated with present day relaysfor'the most part relate to the structural details required to provide cooperative functioningof these three components, g

It is, therefore, an object-of the; present invention to providean'electricrelay having a:minimum number of moving-parts, -which will withstand and remain dependable despite .unusual. environmental conditions, such as excessive .vibration, acceleration, and the like.

Another object of-the presentinvention is to provide an. electric relay, which-includes a balanced contact arrangement resulting in equal contactpressure, and which doesnot require the use of springs, pivots, or other structural details susceptible to failure after repeated operation.

Still another object of the present invention is to provide an electric relay which may be economically manufactured and yet, which ,is simple and rugged in its construction.

These and otheriobjects and advantages "of. the present invention are generally attained by providing an electric relay which includes a casing within which is disposed a force meansv in=the form of a permanent magnet; having oneend connected thereto. Solenoid means are also coupled to the casing and positioned a given distance frorntthe. other .end of the magnet. Interposedbetween the other end or free end of the magnet and the solenoid means is a movable contact means which is normally urged towards a first position by the magnet and actuated towards a second position by energization of the solenoid means.

A first stationary contact means is coupled Within the casing and positioned for connection with the movable contact means when the movable contact means is in its first position. Similarly, a second stationary contact means is coupled within the casing and positioned for connection with the movable contact means upon actuation of the latter to its second position.

Preferably, the movable contact means includes three individual contacts (although one or two individual contacts may also be used) whereby balanced contact pressure may be attained. With such an arrangement and suitable lead and terminal connections, a three-pole double throw relay function is attained.

A better understanding of the present invention will be had by reference to the drawings, showing only an illustrative embodiment, and in which:

Figure l is a cross sectional view of the electric relay of the present invention;

Figure 2 is a top elevational view of the movable contact means shown in Figure 1; and

Figure ,3 is a schematic wiring diagram of the relay shown in Figure 1.

Referring now'to the drawings, there is shown in Figure 1 anelectric relay according to the present invention including a casing '10 having disposed therein a permanent magnet 11. The magnet 11 may be supported in any conventional manner'within the casing 10, as from a cover plate not shown.

First stationary contact means are provided in the form of an annular carrier 12 which is suitably mounted within the. casing 10' about the periphery of the magnet 11 and spaced therefrom. The carrier 12 has mounted thereonzaplurality ofcontacts 13, the upper portions of which function as'terminals for the leads indicated. A movable contact means 14-isheld in a position below the carrier 12 by the force of the magnet 11 such that its contacts -15 form an electrical connection with the stationarycontacts 13. The movable contact means 14 or spider, as more clearly shown in Figure 2, has incorporated therein aplunger 16 secured thereto through the meansof a hollow rivet 17.

The plunger16 -is provided with a conical recess 18 adapted to mate with the core of the solenoid assembly,

,the latter .beinggenerally designated-by the numeral 19.

When energyis applied to the solenoid assembly 119,.

the movable contact means or-spider 14 is urged down: wardly towards asecond stationary contact .meansor lower carrier 20. provided with contacts 21. Thelower carrier means 20 may be secured. to the casing 10 by any suitable connections and further supported on the bottom plate- 22 of. the casinglt).

The solenoid structure has .the usual componentsand includesacoil casing 23 enclosing a coil'24, the latter: in turn. surrounding a. core 25. The core 251 has a flanged base portionv 26 and terminates at its free end in a conical ly shaped head adapted to mate with and fit within the conical recess 18. of the, plunger 16. A nonmagnetic on the spider .orlrnovable contact means 14 to the -normal or first position as shown in Figure 1. In such position, the movable contacts 15 of the spider 14 Will be contacting the stationary contacts 13 of the carrier 12. It will be appreciated that although only two sets of contacts 13 andlS are shown in Figure 1 that the unit preferably has three contacts 13 circumferentially spaced and designed to be axially or vertically aligned with the contacts 15 on the spider 14 as indicated in Figure 2. With such a construction, it will be realized that a tripod arrangement is achieved whereby equal contact pressure is provided, respectively, between connecting contacts 13 and 15 in every instance. It will be appreciated that with slight modifications, the spider or movable contact means 14 may be modified in conjunction with the stationary contact means employed so as to include only two contacts or even one contact properly spaced so as to result in a similar balancing of contact pressure. Thus, with two contacts, they could be disposed in diametrical relationship; and, if one contact were used, it would be desirable to have it positioned along the axis of the movable contact means 14.

Referring now to Figure 3, with the arrangement as preferably employed and shown in Figure 1, the terminals 3 30 would be connected through leads to the stationary contact members 13 which in turn would be connected to the movable contact members 15, as indicated by the terminals 32 connected to the bar-like members 33 of Figure 3.

Upon energization of the solenoid 19, as through leads 34- shown in Figure 3, the bar-like members 33 would be actuated so as to come in contact with leads connecting with terminals 31. This schematic movement would be represented in fact by movement of the spider or movable contact means 4 downwardly towards the core 25 such that the movable contacts 15 would contact the stationary contacts 21 provided on the carrier 20. Thus, a threepole, double throw relay operation is achieved.

It will be appreciated that as the plunger 16 comes down into engagement with the upper conical surface of the core 25, the magnetic path of the solenoid 19 will be from the core 25 through the plunger 16 to the head member 28, and thereafter through the casing 23 and back through the base portion 26 of the core 25. The opposing magnetic field of the permanent magnet will be through the casing 10, down through the bottom plate 22, through the casing 23 of the solenoid, through the head 28, and up through the plunger 16 to the other end of the permanent magnet. It is evident with this type of construction that nearly every portion of the relay performs a dual function in not only being employed for mechanical purposes, but also for electromagnetic purposes.

It is further to be noted that the rivet member 17, as heretofore mentioned, functions not only as a means of holding the plunger to the movable contact means or spider 14, but also functions as an escape valve for any air pressure that tends to build up in the cavity 18 as the plunger 16 mates with the upper portion of the core 25.

Although an illustrative embodiment has been shown, it will be appreciated that many changes and modifications may be made in the various structural details and in the contact arrangement. In consequence, it is not the intent to-limit the invention to the particular form shown and described, but rather in accordance with the scope and spirit of the following claims.

What is claimed is:

1. An electric relay comprising: a casing; a permanent magnet disposed within and having one end connected to said casing; solenoid means coupled to said casing and positioned a given distance from the other end of said magnet; floating movable contact means interposed between said solenoid means and said other end of said magnet, said movable contact means including a plunger of magnetic material so as to be normally urged towards a first position by said magnet and actuated towards a second position upon energization of said solenoid means; first stationary contact means coupled within said casing and positioned for connectionwith said movable contact means when said movable contact means is in said first position; and, second stationary contact means coupled within said casing and positioned for connection with said movable contact means upon actuation of said movable contact means to said second position.

2. An electric relay, according to claim 1, in which said solenoid means includes a housing connected to said casing; said housing, said casing, and said plunger forming a part of a magnetic circuit with said permanent magnet when said movable contact means is in said first position.

3. An electric relay, according to claim 1, in which said core is provided with a conically shaped head, and in which said plunger includes a conically shaped recess, said head being adapted to mate with said recess upon actuation of said plunger.

'4. An electric relay, according to claim 3, in which said plunger includes an aperture allowing air to escape from said recess upon mating of said bead in said recess.

5. An electric relay, according to claim 1, in which said movable contact means includes three spaced contact members defining a given plane.

6. An electric relay comprising: a casing; force means coupled to said casing; solenoid means coupled to casing and positioned a given distance from said force means; floating movable contact means interposed between said force means and said solenoid means, said movable contact means being normally urged to a first position by said force means and actuated towards a second position upon energization of said solenoid means, and said movable contact means including three spaced contact members defining a given plane; first stationary contact means coupled within said casing and positioned for connection with said movable contact means when said movable con tact means is in said first position; and, second stationary contact means coupled within said casing and positioned for connection with said movable contact means upon actuation of said movable contact means to said second position.

References Cited in the file of this patent UNITED STATES PATENTS Sauer Mar. 4, 1958 

